The blocks combine essential salt, key minerals, fresh apple flavor, Vitamin A & Vitamin D for a balanced supplement. The Mighty Deer Sweet Apple Blocks contain calcium and phosphorus which are essential to strong bones and antler development. Now deer can get their minerals year round, and they really love them! The 4 lb blocks are referred to as ‘pocket blocks’ because they are the perfect size for dropping into a jacket pocket for placement in strategic areas. Their size makes it easy to carry multiple blocks for placement in several areas keeping deer coming back on a regular basis to get the minerals their bodies crave.